Lattice QCD calculation of the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msubsup><mml:mrow><mml:mi>D</mml:mi></mml:mrow><mml:mrow><mml:mi>s</mml:mi></mml:mrow><mml:mrow><mml:mo>*</mml:mo></mml:mrow></mml:msubsup></mml:mrow></mml:math> radiative decay with (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mn>2</mml:mn><mml:mo>+</mml:mo><mml:mn>1</mml:mn></mml:mrow></mml:math>)-flavor Wilson-clover ensembles

Abstract

We perform a lattice calculation on the radiative decay of <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:msubsup><a:mi>D</a:mi><a:mi>s</a:mi><a:mo>*</a:mo></a:msubsup></a:math> using the (<c:math xmlns:c="http://www.w3.org/1998/Math/MathML" display="inline"><c:mrow><c:mn>2</c:mn><c:mo>+</c:mo><c:mn>1</c:mn></c:mrow></c:math>)-flavor Wilson-clover gauge ensembles generated by CLQCD collaboration. A method allowing us to calculate the form factor with zero transfer momentum is proposed and applied to the radiative transition <e:math xmlns:e="http://www.w3.org/1998/Math/MathML" display="inline"><e:mrow><e:msubsup><e:mrow><e:mi>D</e:mi></e:mrow><e:mrow><e:mi>s</e:mi></e:mrow><e:mrow><e:mo>*</e:mo></e:mrow></e:msubsup><e:mo stretchy="false">→</e:mo><e:msub><e:mrow><e:mi>D</e:mi></e:mrow><e:mrow><e:mi>s</e:mi></e:mrow></e:msub><e:mi>γ</e:mi></e:mrow></e:math> and the Dalitz decay <h:math xmlns:h="http://www.w3.org/1998/Math/MathML" display="inline"><h:mrow><h:msubsup><h:mrow><h:mi>D</h:mi></h:mrow><h:mrow><h:mi>s</h:mi></h:mrow><h:mrow><h:mo>*</h:mo></h:mrow></h:msubsup><h:mo stretchy="false">→</h:mo><h:msub><h:mrow><h:mi>D</h:mi></h:mrow><h:mrow><h:mi>s</h:mi></h:mrow></h:msub><h:msup><h:mrow><h:mi>e</h:mi></h:mrow><h:mrow><h:mo>+</h:mo></h:mrow></h:msup><h:msup><h:mrow><h:mi>e</h:mi></h:mrow><h:mrow><h:mo>−</h:mo></h:mrow></h:msup></h:mrow></h:math>. After a continuum extrapolation using three lattice spacings, we obtain <k:math xmlns:k="http://www.w3.org/1998/Math/MathML" display="inline"><k:mrow><k:mi mathvariant="normal">Γ</k:mi><k:mo stretchy="false">(</k:mo><k:msubsup><k:mrow><k:mi>D</k:mi></k:mrow><k:mrow><k:mi>s</k:mi></k:mrow><k:mrow><k:mo>*</k:mo></k:mrow></k:msubsup><k:mo stretchy="false">→</k:mo><k:msub><k:mrow><k:mi>D</k:mi></k:mrow><k:mrow><k:mi>s</k:mi></k:mrow></k:msub><k:mi>γ</k:mi><k:mo stretchy="false">)</k:mo><k:mo>=</k:mo><k:mn>0.0549</k:mn><k:mo stretchy="false">(</k:mo><k:mn>54</k:mn><k:mo stretchy="false">)</k:mo><k:mtext> </k:mtext><k:mtext> </k:mtext><k:mi>keV</k:mi></k:mrow></k:math>, where the error is purely statistical. The result is consistent with previous lattice calculations but with a error reduced to only a fifth of the before. The Dalitz decay rate is also calculated for the first time and the ratio with the radiative transition is found to be <s:math xmlns:s="http://www.w3.org/1998/Math/MathML" display="inline"><s:msub><s:mi>R</s:mi><s:mrow><s:mi>e</s:mi><s:mi>e</s:mi></s:mrow></s:msub><s:mo>=</s:mo><s:mn>0.624</s:mn><s:mo stretchy="false">(</s:mo><s:mn>3</s:mn><s:mo stretchy="false">)</s:mo><s:mo>%</s:mo></s:math>. A total decay width of <w:math xmlns:w="http://www.w3.org/1998/Math/MathML" display="inline"><w:msubsup><w:mi>D</w:mi><w:mi>s</w:mi><w:mo>*</w:mo></w:msubsup></w:math> can then be determined as 0.0587(54) keV taking into account the experimental branching fraction. Combining with the most recent experimental measurement on the branching fraction of the purely leptonic decay <y:math xmlns:y="http://www.w3.org/1998/Math/MathML" display="inline"><y:mrow><y:msubsup><y:mrow><y:mi>D</y:mi></y:mrow><y:mrow><y:mi>s</y:mi></y:mrow><y:mrow><y:mo>+</y:mo><y:mo>,</y:mo><y:mo>*</y:mo></y:mrow></y:msubsup><y:mo stretchy="false">→</y:mo><y:msup><y:mrow><y:mi>e</y:mi></y:mrow><y:mrow><y:mo>+</y:mo></y:mrow></y:msup><y:msub><y:mrow><y:mi>ν</y:mi></y:mrow><y:mrow><y:mi>e</y:mi></y:mrow></y:msub></y:mrow></y:math>, we obtain the quantity <bb:math xmlns:bb="http://www.w3.org/1998/Math/MathML" display="inline"><bb:mrow><bb:msub><bb:mrow><bb:mi>f</bb:mi></bb:mrow><bb:mrow><bb:msubsup><bb:mrow><bb:mi>D</bb:mi></bb:mrow><bb:mrow><bb:mi>s</bb:mi></bb:mrow><bb:mrow><bb:mo>*</bb:mo></bb:mrow></bb:msubsup></bb:mrow></bb:msub><bb:mo stretchy="false">|</bb:mo><bb:msub><bb:mrow><bb:mi>V</bb:mi></bb:mrow><bb:mrow><bb:mi>c</bb:mi><bb:mi>s</bb:mi></bb:mrow></bb:msub><bb:mo stretchy="false">|</bb:mo><bb:mo>=</bb:mo><bb:mo stretchy="false">(</bb:mo><bb:msubsup><bb:mrow><bb:mn>190.5</bb:mn></bb:mrow><bb:mrow><bb:mo>−</bb:mo><bb:mn>41</bb:mn><bb:mo>.</bb:mo><bb:msub><bb:mrow><bb:mn>7</bb:mn></bb:mrow><bb:mrow><bb:mi>stat</bb:mi></bb:mrow></bb:msub></bb:mrow><bb:mrow><bb:mo>+</bb:mo><bb:mn>55.1</bb:mn></bb:mrow></bb:msubsup><bb:mo>±</bb:mo><bb:msub><bb:mrow><bb:mn>12.6</bb:mn></bb:mrow><bb:mrow><bb:mi>syst</bb:mi></bb:mrow></bb:msub><bb:mo stretchy="false">)</bb:mo><bb:mtext> </bb:mtext><bb:mtext> </bb:mtext><bb:mi>MeV</bb:mi></bb:mrow></bb:math>, where the stat. is only the statistical error from the experiment, and syst. results from the experimental systematic uncertainty and the lattice statistical error. Our result leads to an improved systematic uncertainty compared to <hb:math xmlns:hb="http://www.w3.org/1998/Math/MathML" display="inline"><hb:mrow><hb:msub><hb:mrow><hb:mn>42.7</hb:mn></hb:mrow><hb:mrow><hb:mi>syst</hb:mi></hb:mrow></hb:msub></hb:mrow></hb:math> obtained using previous lattice prediction of total decay width 0.070(28) keV as the input. Published by the American Physical Society 2024

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